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Objective To construct miRNA-29b1 gene knockout mice based on CRISPR/Cas9 technology. Methods To design and synthesize sgRNA according to the miRNA-29b1 sequence in Genbank .sgRNA and Cas9 were transcribed to RNA in vitro, these RNA were then microinjected into zygotes of C 57BL/6 mice.After mouse birth, the genome DNA was extracted and sequenced to identify its genotype; meanwhile , real-time PCR was used to assay the expression of miRNA-29b1 in the heart, liver, spleen, lung and kidney of mutated mice .Result A 20 bp sgRNA targeted on miRNA-29b1 was synthesized and transcribed to RNA with Cas 9.After microinjection, miRNA-29b1 gene-mutated mice were obtained.The sequencing results showed that there were two types of genotype for the mutated mice , one was 10 bp deletion, and another was 23 bp deletion accompanied with a 3 bp insertion.Compared with the wild-type mice, the expression of miRNA-29b1 in the heart, liver, spleen, lung and kidney was reduced significantly .Conclusions miRNA-29b1 gene knockout mice are constructed successfully by using CRISPR /Cas9 technology.
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Objective To establish a Chinese hamster model of babesia infection, to find the changing pattern of organs and biochemical parameters in Chinese hamster infected with Babesia, and to promote the detection and treatment of babesiosis.Methods Healthy 5-week old Chinese hamsters were infected by intraperitoneal injection of blood containing Babesia.Blood samples were collected at 0, 2, 4, 6, 8, 10, 12, 14, 16, 23, 30, and 37 days after infection from 5 hamsters at each time point.Blood smears were prepared to detect the parasites using Giemsa staining.ELISA assay was employed to test the IL-2 concentration.The blood biochemical indexes were detected using an automatic biochemical analyzer.DNA was extracted from the whole blood and REAL-TIME RCR was performed to determine the reproduction of Babesia.Aftert the animals were sacrificed, the heart, lung, spleen, liver, and kidney were taken to analyze the changes of organ coefficients.Results The highest level of Babesia in the hamsters occurred on day 4 after the Babesia injection, and then showing a decreasing tendency.However, there was a transient increase on the 12th day after infection.The liver and spleen displayed most extensive response to the infection showing hepatomegaly and splenomegaly, but the variation of heart and kidneys coefficients was within the norm.There were prominent changes of blood cells, especially leucocytes, with two peaks at day 10 and 23 after the Babesia infection.The peak changes of blood biochemical indexes occurred at day 12 after infection.The concentration of serum IL-2 reached a peak on the 10th day after infection.Conclusions The Chinese hamsters display typical characteristics of tick-borne diseases such as hepatomegaly and splenomegaly.The immunological system is activated along with the infection and reaches a highest stage in the second week.Afterwards the Babesia can live in the hamster body for a long period of time.The results of this study provide useful information supporting further studies on the detection, treatment and prevention of Babesiosis.
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Objective To knockout Rag2 and IL2rg genes and construct severe combined immunodeficiency mice based on CRISPR/Cas9 technology. Method Design and synthesis of 25 bp sgRNA were made according to the Rag2 and IL2rg sequences in Genbank. After annealing, sgRNA was cloned into pX330 vector. Recombination plasmid Rag2?sgRNA, IL2rg?sgRN and Cas9 were then transcribed into RNA, these RNA were microinjected into zygotes and the zygotes were transplanted into recipient ICR mice. F0 founders were born and mutated F0 founders mated with wild type mice to obtain F1 generation heterozygous mice. Mutated F1 mice were crossed and got F2 generation homozygous mice. Genotype and phenotype of the knockout mice were identified by sequencing, flow cytometry and xenograft model. Results Rag2?sgRNA and IL2rg?sgRNA recombination plasmids were constructed and transcribed into RNA. After microinjection and mat? ing, F0 founders were born and F2 homozygous mice were obtained. The results of sequencing showed that there were two types of genotype in IL2rg gene, 10 bp or 11 bp deletion;however, there was only one genotype in Rag2 gene, which was 8 bp deletion. Compared with wild?type BALB/c mice, the number of CD3 +, B220 + and NKp46 + cells in peripheral blood of the knockout mice was reduced significantly. After inoculation of human breast cancer cell line SKBR?2HL cells, tumor size in the xenograft mouse model was increased gradually along with time extension. Conclusion CRISPR/Cas9 is an efficient way to mutate Rag2 and IL2rg gene in mice in vivo, leading to aberrant T cells, B cells and NK cells.
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Objective To isolate, culture and identify mouse umbilical cord mesenchymal stem cells( mUCMSCs) and to study whether they can be induced to differentiate into adipocytes, chondrocytes and osteoblasts.Methods The mUCMSCs were isolated and expanded by adherent culture from fresh mouse umbilical cord.The morphological characteris-tics of the resulting cells were observed under inverted phase contrast microscope, and their expression of mesenchymal sur-face markers was identified and analyzed by flow cytometry.Then mUCMSCs were induced to differentiate into chondro-cytes, adipocytes and osteoblasts in vitro.Results Fibroblast-like cells could be isolated from the fresh umbilical cord by adherent culture.These adherent cells highly expressed mesenchymal markers including CD29, CD90 and CD105 while low expression of CD34.The cells were successfully induced to differentiate into chondrocytes, adipocytes and osteoblasts. Conclusions The mUCMSCs isolated from fresh mouse umbilical cord by adherent culture have potential of differentiation into chondrocytes, adipocytes and osteoblasts.
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Objective To screen the splicing isoforms of estrogen receptor βin the Beagle hypothalamic -pituitary -gonadal axis.Methods For ERβmRNA CDS sequence of eight exons, primers were designed confined to the CDS sequences of two sequential exons.Beagle hypothalamus, pituitary, ovary and uterus tissue cDNA were used as template, and corresponding sequences were amplified by PCR.PCR products were sequenced and aligned in the NCBI web site.The correct gene was then analyzed with DNAMAN comparative analysis software and handwork checking up, thus got the ERβsplicing isoforms of Beagle. Results Four beagle ER beta splicing isomers were obtained:exon 4 complete skipping ER βisomer (300 bp missing), two kind of Beagle ERβisoforms with partial exon 4 and partial exon 5 complicated missing (isoformⅠ334 bp missing and isoformⅡ265 bp missing), and exon 7 complete missing ERβsplicing isoforms (181 bp missing).Exon 4 complete skipping and exon 7 complete missing isomers had been obtained full length coding sequence, and the other two splicing isomers were partial coding sequence.Conclusion This project gained four ERβsplicing isomers of Beagle, and that will lay an important foundation for further study of their roles in the Beagle reproductive regulation mechanism.
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Objective To explore the differences in immune responses between Cricetulus barabensis and their albino mutant infected with Trichinella spiralis.Methods The physiological parameters of blood , expression levels of IL-2 protein and IL-6 gene in the spleen were analyzed.Results The level of immune cells and cytokines of Cricetulus barabensis was higher than that in the albino mutant .Conclusions Cricetulus barabensis is a suitable model animal for research on long-term latent infection such as infection with Trichinella spiralis.